It is known to provide wheelchairs or the like to transport persons with limited mobility, such as the infirm, aged, or disabled. Conventional wheelchairs are manually powered devices, either moved by the occupant's own power (generally by pushing enlarged rear wheels) or by another person pushing the wheelchair. Known powered wheelchairs are generally similar in concept to earlier wheelchairs, but have an electric motor to drive the wheels of the wheelchair. These conventional wheelchairs are generally not very stable, and are therefore prone to tipping. Further, electric wheelchairs are often provided with low ground clearance and small wheels, making them only suitable for use on smooth surfaces.
Electric mobility scooters are also available, but again generally have low ground clearance and are therefore generally only suitable for use on relatively smooth ground surfaces.
U.S. Pat. No. 5,782,483, U.S. Pat. No. 4,989,890, U.S. Pat. No. 6,164,674, and U.S. Pat. No. 5,301,964 describe adjustable wheelchairs.
JP 2001-48497, JP 11-92091, JP 53-87424, and US 2003/0168832 describe vehicles with adjustable wheelbases.
JP 5-96922 describes an automobile with height adjustable suspension.
NZ 242929 describes an off-road vehicle.
U.S. Pat. No. 3,825,087 describes an agricultural vehicle.
The applicants are also aware of a Toyota conceptual vehicle named the 1-UNIT.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior alt or form part of the common general knowledge in the art.
It is an object of at least preferred embodiments of the present invention to provide a vehicle that is adjustable so it is suitable for use over a variety of terrains and conditions, or which at least provides the public with a useful alternative.